Peripheral Precocious Puberty Revealing McCune-Albright Syndrome in a Three-Year-Old Girl: A Case Report.

McCune-Albright syndrome (MAS) is a rare genetic disorder characterized by the triad of café-au-lait skin pigmentation, fibrous dysplasia, and peripheral precocious puberty. We report the case of a three-year-old girl presenting with recurrent vaginal bleeding and progressive breast development. Clinical examination revealed café-au-lait macules, and hormonal evaluation showed elevated estradiol levels with suppressed gonadotropins. Pelvic ultrasound demonstrated ovarian cysts. Bone age was advanced compared to chronological age. Additional imaging with technetium-99m bone scintigraphy revealed increased radiotracer uptake in multiple long bones, suggestive of increased bone turnover and supporting skeletal involvement. These findings were consistent with a diagnosis of MAS. The patient was treated with letrozole, resulting in clinical improvement. This case highlights the importance of considering MAS in cases of peripheral precocious puberty and emphasizes the role of multimodal clinical and imaging assessment in supporting the diagnosis.